You cannot make much spiritual progress without clearing a substantial amount of your karmic debts. However you may generate good karma that can act like a 'stock absorber' when your negative karma matures. Practicing advanced spiritual techniques without sufficient good karma would be like driving at high speed on a bumpy road in an old car, and without a shock absorber! That is why in ancient times the disciples had to commit themselves to service in order to balance the acceleration of negative karma.9
For this reason, it is extremely important to serve in proportion to the wisdom you gain from spiritual teachers. The accelerated spiritual development as a result of acquired wisdom will automatically speed up repayment of karmic debts as well.